In a surreal moment, Trump unexpectedly walked into the arena as Cruz was wrapping up his remarks. Delegates chanted Trump’s name, then erupted in a chorus of boos when Cruz continued to resist their appeals.

“Vote for candidates up and down the ticket who you trust to defend our freedom and to be faithful to the Constitution,” Cruz said. While he backed some of Trump’s policy proposals, including building a wall along the U.S.-Mexico border, he mentioned the GOP nominee by name only once.

Cruz’s decision to accept a speaking role at the convention but not explicitly endorse Trump was remarkable, and underscored the deep divisions still coursing through the GOP. It also raised questions about why the Trump campaign invited Cruz to speak – in a headlining role, no less – without getting him to agree to an endorsement.

The stunning moment upended what had been the convention’s most successful night. Taking the stage shortly after Cruz, former House Speaker Newt Gingrich tried to explain away the senator’s lack of support for the nominee.

“Ted Cruz said you can vote your conscience for anyone who will uphold the Constitution,” he said. “In this election there is only one candidate who will uphold the Constitution.”

Later, Trump was turning to his newly named running mate Indiana Gov. Mike Pence to close Day 3 of the convention on a more unifying note. A favorite of evangelicals, Pence was expected to urge conservatives …